This invention relates to grinding machines for industrial and commercial purposes, and more specifically to improvements in an attachment to grinding machines for converting such machines from manual operation to automatic operation. Grinding machines for industrial and commercial applications are widely used and have been especially designed for specific applications in many instances. For example, grinding machines for sharpening circular saw blades are in common usage, wherein such machines include a mounting fixture for holding a circular saw blade and a manually movable grinding wheel for contacting various edges of the saw to grind these edges to a uniform and sharpened condition. The present invention is an improvement in such machines whereby a manually operated grinding machine for sharpening circular saws may be converted into an automatic machine.
Circular saws may be characterized by a number of different parameters, including diameter, number and type of teeth, metal composition, cutting edge shape and bevel, and intended usage. Circular saws also have a number of characteristics in common; included among these characteristics are the desirability of maintaining uniformity in size and shape of the saw teeth, or patterns of teeth, and the desirability that all such teeth have uniformly sharpened cutting edges. Since it is inevitable that all circular saws will become dulled with usage, it is important that equipment which is designed for sharpening such blades be capable of maintaining the uniformity of shape, size and cutting edge which is required.
Carbide tipped saw blades have been in usage for a number of years, and these blades offer the advantage of providing extended use without having their cutting edges become dulled as rapidly as ordinary steel saw blades. Such blades are constructed of steel, but have small carbide tips attached on each of the teeth along the steel cutting face. The carbide tips are formed from extremely hard carbide steel material which wears away and dulls very slowly. When such a blade does become dull it usually requires superior equipment having diamond grinding wheels for adequately sharpening the carbide tips. The preferred embodiment of the present invention relates to an improvement in carbide saw grinders whereby such grinders may be converted from manual operation to automatic operation. Such a manual carbide saw grinder may be found in a machine manufactured by Foley Manufacturing Company, Minneapolis, Minn., as Model 357, and other similar model designations. The preferred embodiment of the present invention is disclosed with reference to attachment to the foregoing machine, recognizing that adaptations may be made to the invention for permitting its attachment to other similar manually operated saw grinders.
In general, there are three grinding operations that can be performed to sharpen a carbide tipped saw blade. These three operations are face grinding, top grinding and side grinding. Face grinding is the sharpening of the carbide tip face of each sawtooth which engages the material to be cut. Top grinding involves sharpening of the outer edge portions of each of the saw teeth around the blade circumference, and is usually intended to provide uniformity of tooth height to maintain perfect roundness of the saw blade. Side grinding refers to a grinding operation performed on the flat sides of the blade, and specifically on the carbide tip edges which are parallel to the blade flat surface. Top grinding and face grinding require independent and precision grinding operations for each tooth on the saw blade. In any grinding operation entailing the sharpening of carbide tipped saw blades, it is usually necessary to only grind a few thousandths of an inch in order to restore the sharpness of the saw teeth. Therefore the grinding equipment must be capable of precision and repeatable operation to within tolerances of better than a few thousandths of an inch.